This paper aims to present an innovative multi-criteria tool for the comparison of alternative and conventional on board energy systems for maritime vessels, both for hotel and propulsion loads, depending on the mission taken into account. The tool, developed in Matlab environment and named HELM (Helper for Energy Layouts in Maritime applications), includes an extended and up-to-date market database of many technologies in terms of power units and suitable fuel storage systems. A wide range of maps has been created, correlating costs, volumes, weights, emissions and fuel environmental hazards with the installed power and the operational hours, given by the user as input. In this work, the competitiveness of hydrogen technologies (PEM fuel cells and different H2 storage systems) is demonstrated for two different maritime vessels typologies. It is worth noting that the multi-criteria analysis carried out has a general approach, allowing it to give preliminary information on the energy system, in order to respect new requirements (e.g. more and more stringent normative in terms of pollutant emissions in ports and restricted areas). HELM can be used for many design approaches, either for a new ship project or for already existing ships retrofit; furthermore, the database can be easily extended to other generation and storage technologies, as well as to different kind of vessels.
